A wastewater analysis conducted by the European Monitoring Center for Drugs and Drug Addiction (EMCDDA) has identified Amsterdam’s wastewater as containing the most ecstasy residuals in all Europe. The analysis tested the wastewater 56 European cities in 19 countries in an effort to “explore the drug-taking habits” those residing there. Conducted regularly since 2011, the study maintains that the results “provide a valuable snapshot the drug flow through the cities involved, revealing marked geographical variations.”

In addition to ecstasy, the analysis also found high trace levels cocaine in Amsterdam’s wastewater, leading Amsterdam to place seventh in the study for cocaine concentration. Belgium, the Netherlands, Spain, and the United Kingdom also yielded elevated cocaine concentrations, while Eastern European countries alternatively had the lowest. Eindhoven was secondary to Amsterdam in ecstasy residual levels, but had the highest amphetamine residues. The study attributes the increased concentrations in Amsterdam and Eindhoven to the production and consumption both ecstasy and amphetamines in Europe.

The EMCDDA determined that no major trends in drug use have materialized since the study’s inception, signifying a relative consistency in substance use across the cities included in the analysis’ purview. “Overall, the data related to amphetamine and methamphetamine from the seven monitoring campaigns showed no major changes in the general patterns use observed,” the report said.

The EMCDDA did, however, identify an “expected” increase in some areas. As the analysis notes, “Over the seven years monitoring the highest MDMA loads were consistently found in the wastewater cities in Belgium and the Netherlands. Looking at longer term trends, in most cities with at least six data points wastewater MDMA loads were higher in 2017 than in 2011, with sharp increases observed in some cities, including Antwerp and Amsterdam. For most those cities that observed sharp increases for the period 2011–16, the trend seems to have stabilised in 2017.”

The full study can be read, .